proposal for eventually deprecating OIDs on user tables that I posted
earlier to pgsql-hackers. pg_dump now always specifies WITH OIDS or
WITHOUT OIDS when dumping a table. The documentation has been updated.
Neil Conway
discussion on pgsql-hackers: in READ COMMITTED mode we just have to force
a QuerySnapshot update in the trigger, but in SERIALIZABLE mode we have
to run the scan under a current snapshot and then complain if any rows
would be updated/deleted that are not visible in the transaction snapshot.
to allow es_snapshot to be set to SnapshotNow rather than a query snapshot.
This solves a bug reported by Wade Klaver, wherein triggers fired as a
result of RI cascade updates could misbehave.
really general fix might be difficult, I believe the only case where
AtCommit_Notify could see an uncommitted tuple is where the other guy
has just unlistened and not yet committed. The best solution seems to
be to just skip updating that tuple, on the assumption that the other
guy does not want to hear about the notification anyway. This is not
perfect --- if the other guy rolls back his unlisten instead of committing,
then he really should have gotten this notify. But to do that, we'd have
to wait to see if he commits or not, or make UNLISTEN hold exclusive lock
on pg_listener until commit. Either of these answers is deadlock-prone,
not to mention horrible for interactive performance. Do it this way
for now. (What happened to that project to do LISTEN/NOTIFY in memory
with no table, anyway?)
handle multiple 'formats' for data I/O. Restructure CommandDest and
DestReceiver stuff one more time (it's finally starting to look a bit
clean though). Code now matches latest 3.0 protocol document as far
as message formats go --- but there is no support for binary I/O yet.
DestReceiver pointers instead of just CommandDest values. The DestReceiver
is made at the point where the destination is selected, rather than
deep inside the executor. This cleans up the original kluge implementation
of tstoreReceiver.c, and makes it easy to support retrieving results
from utility statements inside portals. Thus, you can now do fun things
like Bind and Execute a FETCH or EXPLAIN command, and it'll all work
as expected (e.g., you can Describe the portal, or use Execute's count
parameter to suspend the output partway through). Implementation involves
stuffing the utility command's output into a Tuplestore, which would be
kind of annoying for huge output sets, but should be quite acceptable
for typical uses of utility commands.
the column by table OID and column number, if it's a simple column
reference. Along the way, get rid of reskey/reskeyop fields in Resdoms.
Turns out that representation was not convenient for either the planner
or the executor; we can make the planner deliver exactly what the
executor wants with no more effort.
initdb forced due to change in stored rule representation.
which does the same thing. Perhaps at one time there was a reason to
allow plan nodes to store their result types in different places, but
AFAICT that's been unnecessary for a good while.
(materialization into a tuple store) discussed on pgsql-hackers earlier.
I've updated the documentation and the regression tests.
Notes on the implementation:
- I needed to change the tuple store API slightly -- it assumes that it
won't be used to hold data across transaction boundaries, so the temp
files that it uses for on-disk storage are automatically reclaimed at
end-of-transaction. I added a flag to tuplestore_begin_heap() to control
this behavior. Is changing the tuple store API in this fashion OK?
- in order to store executor results in a tuple store, I added a new
CommandDest. This works well for the most part, with one exception: the
current DestFunction API doesn't provide enough information to allow the
Executor to store results into an arbitrary tuple store (where the
particular tuple store to use is chosen by the call site of
ExecutorRun). To workaround this, I've temporarily hacked up a solution
that works, but is not ideal: since the receiveTuple DestFunction is
passed the portal name, we can use that to lookup the Portal data
structure for the cursor and then use that to get at the tuple store the
Portal is using. This unnecessarily ties the Portal code with the
tupleReceiver code, but it works...
The proper fix for this is probably to change the DestFunction API --
Tom suggested passing the full QueryDesc to the receiveTuple function.
In that case, callers of ExecutorRun could "subclass" QueryDesc to add
any additional fields that their particular CommandDest needed to get
access to. This approach would work, but I'd like to think about it for
a little bit longer before deciding which route to go. In the mean time,
the code works fine, so I don't think a fix is urgent.
- (semi-related) I added a NO SCROLL keyword to DECLARE CURSOR, and
adjusted the behavior of SCROLL in accordance with the discussion on
-hackers.
- (unrelated) Cleaned up some SGML markup in sql.sgml, copy.sgml
Neil Conway
utility statement (DeclareCursorStmt) with a SELECT query dangling from
it, rather than a SELECT query with a few unusual fields in it. Add
code to determine whether a planned query can safely be run backwards.
If DECLARE CURSOR specifies SCROLL, ensure that the plan can be run
backwards by adding a Materialize plan node if it can't. Without SCROLL,
you get an error if you try to fetch backwards from a cursor that can't
handle it. (There is still some discussion about what the exact
behavior should be, but this is necessary infrastructure in any case.)
Along the way, make EXPLAIN DECLARE CURSOR work.
nodes where it's not really necessary. In many cases where the scan node
is not the topmost plan node (eg, joins, aggregation), it's possible to
just return the table tuple directly instead of generating an intermediate
projection tuple. In preliminary testing, this reduced the CPU time
needed for 'SELECT COUNT(*) FROM foo' by about 10%.
given any malloc block until something is first allocated in it; but
thereafter, MemoryContextReset won't release that first malloc block.
This preserves the quick-reset property of the original policy, without
forcing 8K to be allocated to every context whether any of it is ever
used or not. Also, remove some more no-longer-needed explicit freeing
during ExecEndPlan.
a per-query memory context created by CreateExecutorState --- and destroyed
by FreeExecutorState. This provides a final solution to the longstanding
problem of memory leaked by various ExecEndNode calls.
execution state trees, and ExecEvalExpr takes an expression state tree
not an expression plan tree. The plan tree is now read-only as far as
the executor is concerned. Next step is to begin actually exploiting
this property.
so that all executable expression nodes inherit from a common supertype
Expr. This is somewhat of an exercise in code purity rather than any
real functional advance, but getting rid of the extra Oper or Func node
formerly used in each operator or function call should provide at least
a little space and speed improvement.
initdb forced by changes in stored-rules representation.
to plan nodes, not vice-versa. All executor state nodes now inherit from
struct PlanState. Copying of plan trees has been simplified by not
storing a list of SubPlans in Plan nodes (eliminating duplicate links).
The executor still needs such a list, but it can build it during
ExecutorStart since it has to scan the plan tree anyway.
No initdb forced since no stored-on-disk structures changed, but you
will need a full recompile because of node-numbering changes.
-hackers a couple days ago.
Notes/caveats:
- added regression tests for the new functionality, all
regression tests pass on my machine
- added pg_dump support
- updated PL/PgSQL to support per-statement triggers; didn't
look at the other procedural languages.
- there's (even) more code duplication in trigger.c than there
was previously. Any suggestions on how to refactor the
ExecXXXTriggers() functions to reuse more code would be
welcome -- I took a brief look at it, but couldn't see an
easy way to do it (there are several subtly-different
versions of the code in question)
- updated the documentation. I also took the liberty of
removing a big chunk of duplicated syntax documentation in
the Programmer's Guide on triggers, and moving that
information to the CREATE TRIGGER reference page.
- I also included some spelling fixes and similar small
cleanups I noticed while making the changes. If you'd like
me to split those into a separate patch, let me know.
Neil Conway
before commit, not after :-( --- the original coding is not only unsafe
if an error occurs while it's processing, but it generates an invalid
sequence of WAL entries. Resurrect 7.2 logic for deleting items when
no longer needed. Use an enum instead of random macros. Editorialize
on names used for routines and constants. Teach backend/nodes routines
about new field in CreateTable struct. Add a regression test.
query that uses it. This ensures that triggers will be applied consistently
throughout a query even if someone commits changes to the relation's
pg_class.reltriggers field meanwhile. Per crash report from Laurette Cisneros.
While at it, simplify memory management in relcache.c, which no longer
needs the old hack to try to keep trigger info in the same place over
a relcache entry rebuild. (Should try to fix rd_att and rewrite-rule
access similarly, someday.) And make RelationBuildTriggers simpler and
more robust by making it build the trigdesc in working memory and then
CopyTriggerDesc() into cache memory.
executor should not return the tuple as successfully marked, because in
fact it's been deleted. Not clear that this case has ever been seen
in practice (I think you'd have to write a SELECT FOR UPDATE that calls
a function that deletes some row the SELECT will visit later...) but we
should be consistent. Also add comments to several other places that
got it right but didn't explain what they were doing.
(overlaying low byte of page size) and add HEAP_HASOID bit to t_infomask,
per earlier discussion. Simplify scheme for overlaying fields in tuple
header (no need for cmax to live in more than one place). Don't try to
clear infomask status bits in tqual.c --- not safe to do it there. Don't
try to force output table of a SELECT INTO to have OIDs, either. Get rid
of unnecessarily complex three-state scheme for TupleDesc.tdhasoids, which
has already caused one recent failure. Improve documentation.
should be pretty safe in practice, but it's probably better to be safe
than sorry.
I was actually looking for cases where NAMEDATALEN is assumed to be
32, but only found one. That's fixed too, as well as a few bits of
code cleanup.
Neil Conway
> There's no longer a separate call to heap_storage_create in that routine
> --- the right place to make the test is now in the storage_create
> boolean parameter being passed to heap_create. A simple change, but
> it passeth patch's understanding ...
Thanks.
Attached is a patch against cvs tip as of 8:30 PM PST or so. Turned out
that even after fixing the failed hunks, there was a new spot in
bufmgr.c which needed to be fixed (related to temp relations;
RelationUpdateNumberOfBlocks). But thankfully the regression test code
caught it :-)
Joe Conway
ERROR: ExecInsert: rejected due to CHECK constraint insert_con
To be like this:
ERROR: ExecInsert: rejected due to CHECK constraint "insert_con" on
"insert_tbl"
Updated regression tests to match.
I got sick of seeing 'rejected due to CHECK constraint "$1" in my log and
not being able to find the bug in our website code...
Christopher Kings-Lynne
bitmap, if present).
Per Tom Lane's suggestion the information whether a tuple has an oid
or not is carried in the tuple descriptor. For debugging reasons
tdhasoid is of type char, not bool. There are predefined values for
WITHOID, WITHOUTOID and UNDEFOID.
This patch has been generated against a cvs snapshot from last week
and I don't expect it to apply cleanly to current sources. While I
post it here for public review, I'm working on a new version against a
current snapshot. (There's been heavy activity recently; hope to
catch up some day ...)
This is a long patch; if it is too hard to swallow, I can provide it
in smaller pieces:
Part 1: Accessor macros
Part 2: tdhasoid in TupDesc
Part 3: Regression test
Part 4: Parameter withoid to heap_addheader
Part 5: Eliminate t_oid from HeapTupleHeader
Part 2 is the most hairy part because of changes in the executor and
even in the parser; the other parts are straightforward.
Up to part 4 the patched postmaster stays binary compatible to
databases created with an unpatched version. Part 5 is small (100
lines) and finally breaks compatibility.
Manfred Koizar
comments on one of the optimizer functions a lot more
clear, adds a summary of the recent KSQO discussion to the
comments in the code, adds regression tests for the bug with
sequence state Tom fixed recently and another reg. test, and
removes some PostQuel legacy stuff: ExecAppend -> ExecInsert,
ExecRetrieve -> ExecSelect, etc.
Error messages remain unchanged until a vote.
Neil Conway
comments on one of the optimizer functions a lot more
clear, adds a summary of the recent KSQO discussion to the
comments in the code, adds regression tests for the bug with
sequence state Tom fixed recently and another reg. test, and
removes some PostQuel legacy stuff: ExecAppend -> ExecInsert,
ExecRetrieve -> ExecSelect, etc. This was changed because the
elog() messages from this routine are user-visible, so we
should be using the SQL terms.
Neil Conway
transaction, so as to avoid returning them out of the index AM. Saves
repeated heap_fetch operations on frequently-updated rows. Also detect
queries on unique keys (equality to all columns of a unique index), and
don't bother continuing scan once we have found first match.
Killing is implemented in the btree and hash AMs, but not yet in rtree
or gist, because there isn't an equally convenient place to do it in
those AMs (the outer amgetnext routine can't do it without re-pinning
the index page).
Did some small cleanup on APIs of HeapTupleSatisfies, heap_fetch, and
index_insert to make this a little easier.
in snapshots, per my proposal of a few days ago. Also, tweak heapam.c
routines (heap_insert, heap_update, heap_delete, heap_mark4update) to
be passed the command ID to use, instead of doing GetCurrentCommandID.
For catalog updates they'll still get passed current command ID, but
for updates generated from the main executor they'll get passed the
command ID saved in the snapshot the query is using. This should fix
some corner cases associated with functions and triggers that advance
current command ID while an outer query is still in progress.
some kibitzing from Tom Lane. Not everything works yet, and there's
no documentation or regression test, but let's commit this so Joe
doesn't need to cope with tracking changes in so many files ...
pg_database, pg_shadow, pg_group, all of which now have potentially-long
fields. Along the way, get rid of SharedSystemRelationNames list: shared
rels are now identified in their include/pg_catalog/*.h files by a
BKI_SHARED_RELATION macro, while indexes and toast rels inherit sharedness
automatically from their parent table. Fix some bugs with failure to detoast
pg_group.grolist during ALTER GROUP.
messages more uniform and internationalizable: the global array
aclcheck_error_strings[] is gone in favor of a subroutine
aclcheck_error(). Partial implementation of namespace-related
permission checks --- not all done yet.
have been divided according to the type of object manipulated - so ALTER
TABLE code is in tablecmds.c, aggregate commands in aggregatecmds.c and
so on.
A few common support routines remain in define.c (prototypes in
src/include/commands/defrem.h).
No code has been changed except for includes to reflect the new files.
The prototypes for aggregatecmds.c, functioncmds.c, operatorcmds.c,
and typecmds.c remain in src/include/commands/defrem.h.
From John Gray <jgray@azuli.co.uk>
in schemas other than the system namespace; however, there's no search
path yet, and not all operations work yet on tables outside the system
namespace.
objects to be privilege-checked. Some change in their APIs would be
necessary no matter what in the schema environment, and simply getting
rid of the name-based interface entirely seems like the best way.
the parsetree representation. As yet we don't *do* anything with schema
names, just drop 'em on the floor; but you can enter schema-compatible
command syntax, and there's even a primitive CREATE SCHEMA command.
No doc updates yet, except to note that you can now extract a field
from a function-returning-row's result with (foo(...)).fieldname.
o Change all current CVS messages of NOTICE to WARNING. We were going
to do this just before 7.3 beta but it has to be done now, as you will
see below.
o Change current INFO messages that should be controlled by
client_min_messages to NOTICE.
o Force remaining INFO messages, like from EXPLAIN, VACUUM VERBOSE, etc.
to always go to the client.
o Remove INFO from the client_min_messages options and add NOTICE.
Seems we do need three non-ERROR elog levels to handle the various
behaviors we need for these messages.
Regression passed.
now just below FATAL in server_min_messages. Added more text to
highlight ordering difference between it and client_min_messages.
---------------------------------------------------------------------------
REALLYFATAL => PANIC
STOP => PANIC
New INFO level the prints to client by default
New LOG level the prints to server log by default
Cause VACUUM information to print only to the client
NOTICE => INFO where purely information messages are sent
DEBUG => LOG for purely server status messages
DEBUG removed, kept as backward compatible
DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1 added
DebugLvl removed in favor of new DEBUG[1-5] symbols
New server_min_messages GUC parameter with values:
DEBUG[5-1], INFO, NOTICE, ERROR, LOG, FATAL, PANIC
New client_min_messages GUC parameter with values:
DEBUG[5-1], LOG, INFO, NOTICE, ERROR, FATAL, PANIC
Server startup now logged with LOG instead of DEBUG
Remove debug_level GUC parameter
elog() numbers now start at 10
Add test to print error message if older elog() values are passed to elog()
Bootstrap mode now has a -d that requires an argument, like postmaster
are now both invoked once per received SQL command (raw parsetree) from
pg_exec_query_string. BeginCommand is actually just an empty routine
at the moment --- all its former operations have been pushed into tuple
receiver setup routines in printtup.c. This makes for a clean distinction
between BeginCommand/EndCommand (once per command) and the tuple receiver
setup/teardown routines (once per ExecutorRun call), whereas the old code
was quite ad hoc. Along the way, clean up the calling conventions for
ExecutorRun a little bit.
default, but OIDS are removed from many system catalogs that don't need them.
Some interesting side effects: TOAST pointers are 20 bytes not 32 now;
pg_description has a three-column key instead of one.
Bugs fixed in passing: BINARY cursors work again; pg_class.relhaspkey
has some usefulness; pg_dump dumps comments on indexes, rules, and
triggers in a valid order.
initdb forced.
report on old-style functions invoked by RI triggers. We had a number of
other places that were being sloppy about which memory context FmgrInfo
subsidiary data will be allocated in. Turns out none of them actually
cause a problem in 7.1, but this is for arcane reasons such as the fact
that old-style triggers aren't supported anyway. To avoid getting burnt
later, I've restructured the trigger support so that we don't keep trigger
FmgrInfo structs in relcache memory. Some other related cleanups too:
it's not really necessary to call fmgr_info at all while setting up
the index support info in relcache entries, because those ScanKeyEntry
structs are never used to invoke the functions. This should speed up
relcache initialization a tiny bit.
the same tuple slot that the raw tuple came from, because that slot has
the wrong tuple descriptor. Store it into its own slot with the correct
descriptor, instead. This repairs problems with SPI functions seeing
inappropriate tuple descriptors --- for example, plpgsql code failing to
cope with SELECT FOR UPDATE.
trees (mostly my fault). Repair. Also fix long-standing bug in ExecReplace:
after recomputing a concurrently updated tuple, we must recheck constraints.
Make EvalPlanQual leak memory with somewhat less enthusiasm than before,
although plugging leaks fully will require more changes than I care to risk
in a dot-release.
allocated by plan nodes are not leaked at end of query. This doesn't
really matter for normal queries, but it sure does for queries invoked
repetitively inside SQL functions. Clean up some other grotty code
associated with tupdescs, and fix a few other memory leaks exposed by
tests with simple SQL functions.
an error as we used to. In an OUTER JOIN scenario, retrieving a null
CTID from one of the input relations is entirely expected. We still
want to lock the input rows from the other relations, so just ignore
the null and keep going.
joins, and clean things up a good deal at the same time. Append plan node
no longer hacks on rangetable at runtime --- instead, all child tables are
given their own RT entries during planning. Concept of multiple target
tables pushed up into execMain, replacing bug-prone implementation within
nodeAppend. Planner now supports generating Append plans for inheritance
sets either at the top of the plan (the old way) or at the bottom. Expanding
at the bottom is appropriate for tables used as sources, since they may
appear inside an outer join; but we must still expand at the top when the
target of an UPDATE or DELETE is an inheritance set, because we actually need
a different targetlist and junkfilter for each target table in that case.
Fortunately a target table can't be inside an outer join... Bizarre mutual
recursion between union_planner and prepunion.c is gone --- in fact,
union_planner doesn't really have much to do with union queries anymore,
so I renamed it grouping_planner.
ExecutorRun. This allows LIMIT to work in a view. Also, LIMIT in a
cursor declaration will behave in a reasonable fashion, whereas before
it was overridden by the FETCH count.
SQL92 semantics, including support for ALL option. All three can be used
in subqueries and views. DISTINCT and ORDER BY work now in views, too.
This rewrite fixes many problems with cross-datatype UNIONs and INSERT/SELECT
where the SELECT yields different datatypes than the INSERT needs. I did
that by making UNION subqueries and SELECT in INSERT be treated like
subselects-in-FROM, thereby allowing an extra level of targetlist where the
datatype conversions can be inserted safely.
INITDB NEEDED!
(Don't forget that an alias is required.) Views reimplemented as expanding
to subselect-in-FROM. Grouping, aggregates, DISTINCT in views actually
work now (he says optimistically). No UNION support in subselects/views
yet, but I have some ideas about that. Rule-related permissions checking
moved out of rewriter and into executor.
INITDB REQUIRED!
for views. Views are now have a "relkind" of
RELKIND_VIEW instead of RELKIND_RELATION.
Also, views no longer have actual heap storage
files.
The following changes were made
1. CREATE VIEW sets the new relkind
2. The executor complains if a DELETE or
INSERT references a view.
3. DROP RULE complains if an attempt is made
to delete a view SELECT rule.
4. CREATE RULE "_RETmytable" AS ON SELECT TO mytable DO INSTEAD ...
1. checks to make sure mytable is empty.
2. sets the relkind to RELKIND_VIEW.
3. deletes the heap storage files.
5. LOCK myview is not allowed. :)
6. the regression test type_sanity was changed to
account for the new relkind value.
7. CREATE INDEX ON myview ... is not allowed.
8. VACUUM myview is not allowed.
VACUUM automatically skips views when do the entire
database.
9. TRUNCATE myview is not allowed.
THINGS LEFT TO THINK ABOUT
o pg_views
o pg_dump
o pgsql (\d \dv)
o Do we really want to be able to inherit from views?
o Is 'DROP TABLE myview' OK?
--
Mark Hollomon
user is now defined in terms of the user id, the user name is only computed
upon request (for display purposes). This is kind of the opposite of the
previous state, which would maintain the user name and compute the user id
for permission checks.
Besides perhaps saving a few cycles (integer vs string), this now creates a
single point of attack for changing the user id during a connection, for
purposes of "setuid" functions, etc.
right circumstances a hash join executed as a DECLARE CURSOR/FETCH
query would crash the backend. Problem as seen in current sources was
that the hash tables were stored in a context that was a child of
TransactionCommandContext, which got zapped at completion of the FETCH
command --- but cursor cleanup executed at COMMIT expected the tables
to still be valid. I haven't chased down the details as seen in 7.0.*
but I'm sure it's the same general problem.
thing when there are multiple result relations. Formerly, during
something like 'UPDATE foo*', foo's constraints and *only* foo's
constraints would be applied to all foo's children. Wrong-o ...
memory contexts. Currently, only leaks in expressions executed as
quals or projections are handled. Clean up some old dead cruft in
executor while at it --- unused fields in state nodes, that sort of thing.
Special handling of TOAST relations during VACUUM. TOAST relations
are vacuumed while the lock on the master table is still active.
The ANALYZE flag doesn't propagate to their vacuuming because the
toaster access routines allways use index access ignoring stats, so
why compute them at all.
Protection of TOAST relations against normal INSERT/UPDATE/DELETE
while offering SELECT for debugging purposes.
Jan
Don't go through pg_exec_query_dest(), but directly to the execution
routines. Also, extend parameter lists so that there's no need to
change the global setting of allowSystemTableMods, a hack that was
certain to cause trouble in the event of any error.
discussion of 5/19/00). pg_index is now searched for indexes of a
relation using an indexscan. Moreover, this is done once and cached
in the relcache entry for the relation, in the form of a list of OIDs
for the indexes. This list is used by the parser and executor to drive
lookups in the pg_index syscache when they want to know the properties
of the indexes. Net result: index information will be fully cached
for repetitive operations such as inserts.
nodes. The former version failed to check permissions of relations that
were referenced in second and later clauses of UNIONs, and it did not
check permissions of tables referenced via inheritance.
SELECT a FROM t1 tx (a);
Allow join syntax, including queries like
SELECT * FROM t1 NATURAL JOIN t2;
Update RTE structure to hold column aliases in an Attr structure.
from a constraint condition does not violate the constraint (cf. discussion
on pghackers 12/9/99). Implemented by adding a parameter to ExecQual,
specifying whether to return TRUE or FALSE when the qual result is
really NULL in three-valued boolean logic. Currently, ExecRelCheck is
the only caller that asks for TRUE, but if we find any other places that
have the wrong response to NULL, it'll be easy to fix them.
in the TupleDesc that the caller already has (for call from ExecMain) or
can make just as easily as ExecInitJunkFilter() can (for call from
ExecAppend). Also, don't bother to build a junk filter for an INSERT
operation that doesn't actually need one, which is the normal case.
mentioned in FROM but not elsewhere in the query: such tables should be
joined over anyway. Aside from being more standards-compliant, this allows
removal of some very ugly hacks for COUNT(*) processing. Also, allow
HAVING clause without aggregate functions, since SQL does. Clean up
CREATE RULE statement-list syntax the same way Bruce just fixed the
main stmtmulti production.
CAUTION: addition of a field to RangeTblEntry nodes breaks stored rules;
you will have to initdb if you have any rules.
Implements the CREATE CONSTRAINT TRIGGER and SET CONSTRAINTS commands.
TODO:
Generic builtin trigger procedures
Automatic execution of appropriate CREATE CONSTRAINT... at CREATE TABLE
Support of new trigger type in pg_dump
Swapping of huge # of events to disk
Jan
* Buffer refcount cleanup (per my "progress report" to pghackers, 9/22).
* Add links to backend PROC structs to sinval's array of per-backend info,
and use these links for routines that need to check the state of all
backends (rather than the slow, complicated search of the ShmemIndex
hashtable that was used before). Add databaseOID to PROC structs.
* Use this to implement an interlock that prevents DESTROY DATABASE of
a database containing running backends. (It's a little tricky to prevent
a concurrently-starting backend from getting in there, since the new
backend is not able to lock anything at the time it tries to look up
its database in pg_database. My solution is to recheck that the DB is
OK at the end of InitPostgres. It may not be a 100% solution, but it's
a lot better than no interlock at all...)
* In ALTER TABLE RENAME, flush buffers for the relation before doing the
rename of the physical files, to ensure we don't get failures later from
mdblindwrt().
* Update TRUNCATE patch so that it actually compiles against current
sources :-(.
You should do "make clean all" after pulling these changes.
additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing). Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM. Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing). A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long. Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.
after ExecEndNode. It must be done! Or we'll be out of free
tuple slots very soon, though slots are freed by ExecEndNode
and ready for reusing.
We didn't see this problem before because of
int nSlots = ExecCountSlotsNode(plan);
TupleTable tupleTable = ExecCreateTupleTable(nSlots + 10);
/* why add ten? - jolly */
code in InitPlan - i.e. extra 10 slots. Simple select uses
3 slots and so it was possible to re-use evaluation plan
3 additional times and didn't get
elog(NOTICE, "Plan requires more slots than are available");
elog(ERROR, "send mail to your local executor guru to fix this");
Changes are obvious and shouldn't be problems with them.
Though, I added Assert(epqstate->es_tupleTable->next == 0)
before EvalPlanQual():ExecInitNode and we'll notice if
something is still wrong. Is it better to change Assert
to elog(ERROR) ?
change functionality, but makes the code more ANSI C'ish.
My AIX xlc compiler barfs on all of these. Can someone please
review and apply to current.
<<port.patch>>
Thanks
Andreas
Ok. I made patches replacing all of "#if FALSE" or "#if 0" to "#ifdef
NOT_USED" for current. I have tested these patches in that the
postgres binaries are identical.
qualification expression trees in the execution state. Prevents from
memory exhaustion on INSERT, UPDATE or COPY to tables that have CHECK
constraints. Speedup against the variant using freeObject() is more than
factor 2.
Jan